1. Technical Field
The present invention relates to a projector suspension device.
2. Related Art
Heretofore, a projector ceiling suspension device has been one to which a projector is fixed suspended from a ceiling. The projector ceiling suspension device, by being installed on the ceiling to fix the projector, causes an image projected from the projector to be projected onto a screen installed on a wall surface of a room, a self-standing screen, or the like. The projector ceiling suspension device is such that, when fixing the projector, the mounting position of the projector is adjusted and fixed in such a way that the image is projected onto a projection region on the screen.
FIGS. 10A and 10B are schematic configuration diagrams of a heretofore known projector ceiling suspension device, where FIG. 10A is a front view, and FIG. 10B a side view.
As shown in FIGS. 10A and 10B, the projector ceiling suspension device includes a ceiling suspension position adjustment mechanism 850. The ceiling suspension position adjustment mechanism 850 is roughly configured of a base member 851 fixed to a ceiling 810, a movable member 852 to which a projector 800 is fixed, pin members 853 which, being disposed in overlapping portions of the side surfaces of the base member 851 and the side surfaces of the movable member 852, make the movable member 852 pivotable with respect to the base member 851, and screw members 855 which fix the base member 851 and movable member 852 by pressing the overlapping portions of the base member 851 and movable member 852 together from either side in the vicinity of each pin member 853. Movement slots 854 having an approximate racetrack shape with each pin member 853 as the center of rotation are formed in portions of the movable member 852 through which the screw members 855 are inserted.
With this structure, it is possible for the projector 800 to move around the pin members 853 within the range of the movement slots 854 (in this case, the angle adjustment of the projector 800 can be carried out). The position adjustment of the projector 800 is to adjust the position of the projector 800 in such a way that a position (a projection position) onto which is projected the image projected from the projector 800 is aligned with a projection region on a screen. The fixation of the projector 800 can be carried out by tightening the screw members 855 while holding the projector 800 subjected to the position adjustment (in this case, the angle adjustment) in the position, thereby pressing the overlapping side surface portions of the base member 851 and movable member 852, and fixing the movable member 852 to the base member 851.
Although not shown, apart from the structure wherein the base member 851 is fixed directly to the ceiling 810, there is also a projector ceiling suspension device of a structure wherein a slide member to which the base member 851 is fixed so as to be slidable in a left-right direction or a front-back direction, or the like, is used between the base member 851 and ceiling 810. The position adjustment of the projector 800 in this case is such that, firstly, a position in the left-right direction or front-back direction of the projector 800 is roughly determined using the slide member, and the slide member and base member 851 are fixed by a screw member, or the like. Subsequently, the heretofore described position adjustment is carried out.
With the ceiling suspension position adjustment mechanism 850 of this kind of projector ceiling suspension device, a position adjustor (a user, or the like, of the projector), needing to carry out the position adjustment by supporting the projector, is burdened with the position adjustment. Also, with this kind of ceiling suspension position adjustment mechanism 850, as space, or the like, between component members is large, taking into account also a movement by an amount equivalent to the space during a screw fixation after the adjustment, and the like, it is impossible to carry out the position adjustment with a high precision.
In particular, when the projector is configured as a so-called short focus projector which, including a projection optical device having a reflecting mirror, causes an image magnification projection onto a screen at a short distance, as a slight misalignment in the position adjustment results in the image being projected with a large misalignment, a higher precision position adjustment (a fine adjustment) has been required in comparison with the heretofore known position adjustment.
Consequently, a projector ceiling suspension device has been demanded wherein it is possible to reliably carry out a high precision position adjustment (a fine adjustment), and a burden of the adjustment is reduced by improving an adjustment operability.